Both of these viruses can be fatal but usually aren’t, and both generally cause severe illness in the same high-risk groups: people with pre-existing illnesses and people of increasing age.
The World Health Organization estimates that there are 3-5 million worldwide cases of severe illness caused by the flu virus every year and about 1 in 10 of those severe cases results in a death.
Currently the fatality rate of Covid-19 disease varies greatly around the world (0.6% in South Korea, 3.3% in Italy and Iran, 4.7% in Hubei province, 0.9% in the rest of China). The true fatality rate may become more apparent as the situation continues, but at the moment, the fatality rate for all confirmed cases of Covid-19 (outside of China) is about 2% (1.8%) and a severe illness is happening in about 20% of all people infected.
The indicators at the moment suggest that the fatality rate for severe cases of Covid-19 appears to be about 1 in 10 (2 in 20), the same as for severe cases of seasonal flu.
The Be Well Team
(Hua Hin, March 6th 2020)